Virtual Reality (VR) and augmented reality (AR) use head-mounted displays (HMDs) to provide the illusion of immersion for a human viewer in a virtual environment. In such an illusion, a viewer may look at an object in the virtual environment. In a conventional HMD, such an object is rendered in stereo so that the viewer's eyes may focus at some vergence (i.e., a focal plane) while looking at the object.